Influence of Salinity on the Resources and Uses of Great Salt Lake

The salinity of Great Salt Lake (GSL) plays a very influential role in shaping the lake’s unique ecological, recreational, and mineral resource uses. This memorandum summarizes a review of the literature and GSL databases to describe critical salinity ranges that influence these resources and uses. It presents a GSL Salinity Matrix intended to provide decision-makers with an important illustration; not to predict how GSL’s salinity will change, but to illustrate the potential consequences of salinity changes.

Benthos Algae Communities of Saline Rivers in the Lake Elton Basin: Taxonomic and Quantitative Structure

For the first time, an assessment was given of the taxonomic and quantitative structure of the phytobenthos of seven saline rivers in the basin of the hypersaline lake Elton (Volgograd Region). Main types of algacenoses developing on substrates were revealed, namely: diatom phytobenthos, communities of diatoms with cyanoprokaryotes, cyanobacterial films and mats, and epiphyton. The phytobenthos consists of local, mosaic-distributed communities with a small similarity of their species composition. The algacenosis structure is determined by Bacillariophyta (with the predominance of species of the genus Navicula) and Cyanoprokaryota (of the genera Phormidium, Leptolyngbya, and Geitlerinema). The abundance and biomass values vary widely, reaching their highest values (109,834–417,472 mln cells/m2 and 523.6–567.6 g/m2 ) in cyanobacterial communities of mesohaline rivers with their salinity up to 16–19 g/L. Mineralization as a factor influencing the structure of communities, most rigidly acts in the estuarine sections of rivers, by controlling the composition of the dominant species. For critical salinity values (> 70 g/L), characteristic structural transformations of communities by the type of replacement of planktonic and benthic Bacillariophyta and Cyanoprokaryota by planktonic Chlorophyta (of the Dunaliella genus) and picoplankton were established.

Innovative Biotechnology of Artificial Reproduction of Fish Populations

С целью повышения эффективности искусственного воспроизводства популяций ценных видов рыб разработаны новые методы управления их размножением, выживаемостью и ростом, которые представлены в виде изобретений. Для управления размножением производителей разработаны методы стимуляции и задержки полового созревания производителей осетровых и костистых рыб. Для стимуляции полового созревания были разработаны препараты изолированной передней и изолированной задней долей гипофиза. Их внедрение в осетроводстве позволило повысить степень их рыбоводного использования в среднем на 15% и достичь экономии гипофиза до 40%. Для задержки полового созревания производителей разработан метод их промышленного резервирования в среде критической солёности 4–8‰, причём как в морской воде, так и в растворах поваренной соли. Производственными испытаниями доказана возможность сохранения рыбоводного качества производителей и получения доброкачественного потомства в этой среде при верхних нерестовых температурах в течение производственно необходимых сроков. С целью заводского воспроизводства природных популяций промысловых рыб разработан метод управления их размножением триадой адекватных экологических факторов ‒ «критической» солёностью, температурой и освещённостью при видоспецифических пороговых воздействиях. На этой основе разработан полносистемный метод воспроизводства популяций ценных видов промысловых рыб (севрюги и Балтийского лосося), охватывающий все этапы заводской биотехники. Новый метод осуществляется путём массовой морской заготовки производителей, получения потомства в морских садках и, после заводского речного выращивания молоди до готовности к миграции, конечного доращивания в морских садках крупной жизнестойкой молоди. Для промышленного внедрения всей предложенной биотехники и круглогодичной аквакультуры разработаны системы водоснабжения рыбоводных заводов и рыбоводных хозяйств на основе внесезонного подземного гидрокондиционирования среды выращивания и на природно-промышленных принципах инженерной экологии. In order to increase the efficiency of artificial reproduction of populations of valuable fish species new methods for managing their reproduction, survival and growth have been developed, which are presented in the form of inventions. To control the reproduction of producers methods have been developed to stimulate and delay puberty of sturgeon and bony fish producers. To stimulate puberty preparations for the isolated anterior and isolated posterior lobes of the pituitary gland have been developed. Their introduction in sturgeon breeding made it possible to increase the degree of their fish farming use by an average of 15% and to achieve a pituitary gland economy of up to 40%. To delay the puberty of producers, a method for their industrial reservation in an environment of critical salinity of 4–8‰ has been developed both in sea water and in solutions of sodium chloride. Production tests have proven the possibility of preserving the fish-breeding quality of producers and obtaining benign offspring in this environment at the upper spawning temperatures during the production required periods of time. With the aim of factory reproduction of natural populations of commercial fish a method has been developed to control their reproduction by a triad of adequate ecological factors – “critical” salinity, temperature and illumination under species-specific threshold effects. On this basis a full-system method of reproducing populations of valuable species of commercial fish (stellate sturgeon and Baltic salmon) has been developed covering all stages of factory biotechnology. The new method is carried out by mass marine harvesting of producers obtaining offspring in sea pens and after the factory river rearing of hatchling until ready for migration the final rearing of large viable juveniles in sea pens. For the industrial introduction of all the proposed biotechnics and year-round aquaculture, water supply systems for fish breeding plants and fish farms were developed on the basis of off-season underground hydroconditioning of the growing environment and on the natural and industrial principles of engineering ecology.

Sharp changes in properties of aqueous sodium chloride solution at “critical” concentrations of the salt

It was shown that some physicochemical properties of aqueous solutions of sodium chloride (contact angle, surface tension, pH, and others) demonstrate a nonlinear dependence on the salt concentration. The maxima or minima in the graphs are most frequently observed near the concentrations of NaCl we call "critical": 3, 5, 7, 12, 17, and 21 g/L. Similar nonlinear peak-shape dependence of the property on salinity was observed in more complex systems containing NaCl (sedimentation rate of mineral suspensions, viscosity of clay pastes, rate of a redox reaction of periodate with amine). We hypothesized that the said critical points of salt concentration may exist when the clusters of water molecules rearrange themselves upon the addition of a definite quantity of salt. The obtained results were used in the discussion of avalanche sedimentation of suspended particulate matter and colloids transported by rivers through the river mixing zones (estuary, delta) and the critical salinity under which the river biota gives place to marine biota.

Effects of cultivation of the fish breeders and juveniles in salt solutions of different concentrations

The aim of the research is to develop new efficient method of fish cultivation in a medium with totally controlled conditions. The main task is the morpho-physiological and piscicultural-biological analysis effects of farming fish- breeders and juvenils in salt solutions of different concentrations. Laboratory and industrial fish contents tests for sea water and salt solutions medium of different salinity have been implemented on the most valuable fish species: russian and stellate sturgeon, rainbow trout, bullhead and roach.The results were evaluated by piscicultural-biological and physiological indicators: content state of hemoglobin, total protein, serum osmolarity, abdominal fluid and urine. Cytomorphometrical analysis of the hypothalamic-hypophysial neurosecreto-ry system (HHNS) status was performed by light and electron microscopy. The enhance effects of fish survival, breeders reproductive quality, youngs growth rates were first established for medi-um with "critical" salinity 4-8‰ For breed-ers originally it was shown the possibility to change sea water on the table salt solution of the same concentration. With such a low concentration of salt a new biostimulating effect of this artificial medium on the fish body was installed, due to the absence of its well-known toxicity. The highest degree of survival and delayed sex maturation of roach and stellate sturgeon were specifically in-stalled for the same concentration of indus-trial salt solutions. The best physiological body state was also shown in this solution (5‰) by physiological and biochemical analysis, regarding minimal losses in hemo-globin and serum protein. Histophysiological analysis of the sevruga HHNS state showed the smallest degree of activity in this solu-tion to the end of the experience, proportion-ate to the severity of stress. Such moderately active HHNS in solution of salt 5‰ clearly indicates the status of the eustress and high HHNS activity for control groups indicates the typical status of the stress. By electron microscopy study HHNS state sevruga and sturgeon in hypertonic salt solutions of dif-ferent concentrations it was shown, that at 17 and 22‰ they were under stress and at 32‰ represented irreversible disstress. All 3 in-stalled stress status depends on the intensity and duration of exposure. Their effects are alternative and therefore are managed, trans-forming from bio-stimulation in reversable stress and, after reaching the limits of physi-ological species cause toxic effect and then a state of disstress and death. The possibility of changing the sea water to industrial salt solution 5-7‰, allowed to develop "A meth-od to reserve fish breeders", which ,however, can not be applied for the young fish breed-ing. So the next stage in the development of this method was to test it already on juvenile and young fish, in order to determine its effective cultivation in this artificial biostim-ulating medium. The results of the search experience on trout fingerlings showed the increased survival and growth in salt solu-tions, especially in 12‰ as compared to con-trol. The first experimental verification of this method on the clarias bullhead finger-lings in the recycling aquacultural system (RAS) showed the largest growth rates in 5‰ salt solution, and its total survival in all variants. Received data and analysis of biostimu-lated effects impact on the body's critical salinity gives the opportunity to develop a fundamentally new way of cultivation of valuable fish species in an artificial biostim-ulated habitat. This technique can allow to manage breeding - obtaining offspring and the cultivation of young fish. It is aimed at improving the efficiency of breeding fish in aquaculture due to the availability of the application for any type of fish farms with the effects of increasing survival rate and young growth rate. It is expected that the change of the sea water with the cheap solu-tion of table salt can be widely practiced at fish plants in various fields and at all stages of fish biotechnology works, especially RAS.